1. Field of Invention
This invention relates to certain nonionic surfactants which when used as co-surfactants in detergent formulations provide improvement in both oily and particulate soil removal. More specifically block copolymers of ethylene oxide and propylene oxide are used in formulations with mixed actives or other oxyalkylated nonionic surfactants. These detergent formulations provide performance improvements beyond those obtained using systems without the subject block copolymers, or those in which the block copolymers are used as the sole surfactant.
2. Description of the Related Art
The use of EO/PO copolymers in detergent formulations has been disclosed. Such uses include those formulations where the copolymers prove to be effective anti-redeposition agents or provide low foaming characteristics to the formulation.
The following patents disclose the use of EO/PO block copolymers as anti-redeposition agents; US 4,724,095, JP 62/4797, PL 130944, and JP 59/6269. U.S. Pat. No. 4,724,095, assigned to Rhone-Poulenc discloses the use of PLURONIC.RTM. polyols as anti-redeposition agents in phosphate built powdered detergents. JP Pat. No. 62/4797, assigned to Kao Soap Company discloses an anionic detergent containing 0.5% PLURONIC.RTM. L-64 as an anti-redeposition agent. PL (Polish) Pat. No. 130944, discloses a polyethylene oxide/polypropylene oxide/polyethylene oxide triblock polymer added to a detergent formulation as an anti-redeposition agent. JP Pat. No. 59/6299, discloses an additive mixture for a detergent/softener composition including a quaternized nitrogen compound, polyethylene glycol, an EO/PO copolymer and polyvinyl alcohol or polyvinyl pyrrollidone, wherein said composition promotes softening and inhibits anti-redeposition. None of the above references disclose or claim compositions with EO/PO copolymers as co-surfactants which improve detergency characteristics.
U.S. Pat. No. 3,101,374, discloses the use of conjugated polyoxyalkylene compounds having a heteric structure as having some carbon soil removal performance. There is no showing of improved detergency performance when these compounds are combined in detergent formulations containing anionic surfactants or other nonionic surfactants.
U.S. Pat. No. 2,677,700 and an article in the Journal of the American Oil Chemical Society, Volume 28, 294 (1951) disclose the use of PLURONIC polyols which exhibit both carbon soil removal and anti-redeposition properties. Neither reference suggests the possibility of enhanced detergency performance when the subject compounds are used in conjunction with other nonionic or anionic surfactants.
Other uses for EO/PO block copolymers disclosed in the literature include, foam reduction (JP 60/235900) and improvement of flow properties in a powder detergent formulation (FR 2617183).